"He is billing himself, and people see him as, the authentic candidate," says Draut, vice president of policy and research at public policy organization Demos. "But, honestly, his whole candidacy is ripped straight from any polling you look at of white working-class voters."

In her new book, "Sleeping Giant: How the New Working Class Will Transform America," Draut argues that the trajectory of the working class has not been sustainable. But she also details a newly emerging working class – one largely made up of people of color and women who hold service jobs – that is overtaking what traditionally has been a manufacturing-based sector dominated by white males.

It's precisely the decline of that traditional working class – along with the frustration and distrust accompanying its demise, which largely have gone ignored by the Republican Party elite – that helped provide an opening for Trump 2016 and its populist-driven agenda.

UNITED STATES - MARCH 02: Donald Trump with Alfred Eisenpreis, New York City Economic Development Administrator. Sketch of new 1,400 room Renovation project of Commodore Hotel. (Photo by NY Daily News Archive via Getty Images)

NEW YORK, NY - 1980: Donald Trump and Ivana Trump attend Roy Cohn's birthday party in February 1980 in New York City. (Photo by Sonia Moskowitz/Getty Images)

Donna Mills and Donald Trump during 1983 Annual American Image Awards at Sheraton Center in New York City, New York, United States. (Photo by Ron Galella, Ltd./WireImage)

Portrait of real estate mogul Donald John Trump (b.1946), smiling slightly and facing to his right, 1983. New York. (Photo by Bachrach/Getty Images)

New York real estate magnates Steve Ross, right, and Donald Trump, left, announce agreement, Thursday, August 1, 1985 in New York, to merge the Houston Gamblers and the New Jersey Generals United States Football League teams. Ross heads a group of investors that last week agreed to buy the troubled Houston franchise. (AP Photo/Marty Lederhandler)

Real estate magnate Donald Trump poses in front of one of three Sikorsky helicopters at New York Port Authority's West 30 Street Heliport on March 22, 1988. (AP Photo/Wilbur Funches)

Billionaire developer Donald Trump, right, waits with his brother Robert for the start of a Casino Control Commission meeting in Atlantic City, N.J., March 29, 1990. Trump was seeking final approval for the Taj Mahal Casino Resort, one of the world's largest casino complexes. (AP Photo)

Developer Donald Trump, center, is flanked by super middleweight champion Thomas Hearns, left, of Detroit, and Michael Olajide of Canada at a news conference in New York Thursday, Feb. 15, 1990. The three announced the super middleweight title bout at Trump Taj Mahal Casino Resort at Atlantic city, N. J on April 28.(AP Photo/Timothy Clary)

Real estate magnate Donald Trump and his girlfriend Marla Maples are seen at the Holyfield-Foreman fight at Trump Plaza in Atlantic City, N.J., April 19, 1991. (AP Photo)

Donald Trump and Daughter Ivanka Trump during Maybelline Presents 1991 Look of the Year at Plaza Hotel in New York City, New York, United States. (Photo by Ron Galella/WireImage)

NEW YORK, NY - APRIL 7: Donald Trump touches 07 April 1993 Marla Maples stomach to confirm published reports that the actress is pregnant with his child. The two arrived for Maples appearance in the Broadway musical 'The Will Rogers Follies'. (Photo credit should read HAI DO/AFP/Getty Images)

NEW YORK, NY - DECEMBER 21: US business tycoon Donald Trump(C) enters the PLaza Hotel in New York past supporters 21 December 1994. Hundreds of supporters showed up at a news conference where Trump denied a New York newspaper report that the Sultan of Brunei had bid 300 million USD to buy the Manhattan hotel. (Photo credit should read DON EMMERT/AFP/Getty Images)

FILE--This is a 1994 file photo of Donald Trump. Trump said Wednesday, Oct. 23, 1996 he has bought the Miss Universe, Miss USA and Miss Teen beauty pageants from ITT. ``It's a done deal,'' Trump said in a telephone interview. ``It's a very, very great entertainment format. It gets very high ratings, it's doing very well and we'll make it even better.'' Trump declined to say how much he paid. Asked if a New York Post source was correct in saying the deal was worth tens of millions of dollars, Trump replied, ``Why not? (AP Photo/Jim Cooper)

Donald Trump and Christine Whitman during Opening of New Warner Bros. Store in Trump Plaza Casino at Trump Plaza Casino in Atlantic City, New Jersey, United States. (Photo by Ron Galella/WireImage)

In this June 7, 1995 file photograph, Donald Trump is seen above the floor of the New York Stock Exchange after taking his flagship Trump Plaza Casino public in New York City. Trump Entertainment Resorts Inc., based in Atlantic City, New Jersey, filed for Chapter 11 protection on Tuesday, Feb. 17, 2009, in the U.S. Bankruptcy Court in New Jersey. Trump and his daughter Ivanka resigned from the company's board Friday, Feb. 13, 2009, after growing frustrated with bondholders. (AP Photo/Kathy Willens,File)

Developer Donald Trump holds an umbrella as he walks Saturday, Nov. 9, 2002, to the 11th green of the Ocean Trail Golf Club in Rancho Palos Verdes, Calif. Trump plans to turn the beleagured golf club into a world class course. Trump intends to close on the golf club by December and hopes to begin improvements by January. He could reopen the course, 20 miles south of Los Angeles, as early as June. (AP Photo/Damian Dovarganes)

Entrepreneur Donald Trump (L) and Rev. Al Sharpton speak at a ribbon cutting ceremony for Sharpton's National Action Network Convention April 5, 2002 in New York City. The group aims to further the development of civil rights. (Photo by Mario Tama/Getty Images)

Donald Trump and his girlfriend Melania Knauss attend the Marc Bouwer/Peta Fall/Winter 2002 Collection show February 14, 2002 during Mercedes-Benz Fashion Week in New York City. (Photo by George De Sota/Getty Images)

FOXBORO, MA - JANUARY 10: Donald Trump stands on the sidelines before the start of the AFC divisional playoffs between the New England Patriots and Tennessee Titans on January 10, 2004 at Gillette Stadium in Foxboro, Massachusetts. Temperatures have reached as low as 7 degrees in the Foxboro area. (Photo by Al Bello/Getty Images)

DES MOINES, IA - MAY 16: Businessman Donald Trump speaks to guests gathered for the Republican Party of Iowa's Lincoln Dinner at the Iowa Events Center on May 16, 2015 in Des Moines, Iowa. The event sponsored by the Republican Party of Iowa gave several Republican presidential hopefuls an opportunity to strengthen their support among Iowa Republicans ahead of the 2016 Iowa caucus. (Photo by Scott Olson/Getty Images)

Developer Donald Trump displays a copy of his net worth during his announcement that he will seek the Republican nomination for president, Tuesday, June 16, 2015, in the lobby of Trump Tower in New York. (AP Photo/Richard Drew)

Below, we take a look at some of the evidence showing the decline of the working class – defined by Draut as Americans without a college education – along with the factors and fears Trump has capitalized on during his rise to the top of the Republican Party pack.

In short, here's why we all should have seen this coming.

Economic Strife

The wages of those in the working class have dropped over the past decades, which – combined with the increasing costs associated with housing and education – have put the American dream increasingly out of reach for many. For men in the working class specifically, the median hourly wage declined by $4.47 (in 2013 dollars) between 1980 and 2012, according to Draut's analysis of Labor Department data.

Many members of the working class also have been trapped in part-time work, needing to hold down several jobs just to make ends meet. Even worse, advocates say wage theft – in which employers don't pay overtime, steal tips or skimp on salary in some other way – is all too common, meaning workers often need to be suspicious of the very companies they are depending on. One poll found that nearly 90 percent of fast-food workers had experienced wage theft.

As evidenced by fewer benefits, unpredictable schedules and frequent safety violations, Draut says today's working class isn't provided the same respect as the working class of her father's day was. And despite a slow but steady economic recovery in the U.S., the working class – which was hit hard by the Great Recession – still has less economic confidence than a year ago, according to Gallup.

The New Populists

In a report on the white working class called "Beyond Guns and God," the Public Religion Research Institute explored the populism among the white working class. The 2012 analysis and accompanying survey data showed that 70 percent of white working-class Americans believed the economic system favored the wealthy, and a majority said that one of the biggest problems facing the U.S. was that not everyone gets an equal chance in life.

Many also believed that capitalism and the free market system were at odds with Christian values. And nearly 8 in 10 blamed the nation's economic problems either somewhat or very much on corporations moving jobs overseas.

Meanwhile, just 1 in 20 white working-class Americans said either abortion or same-sex marriage was the most important issue to their vote.

Enter Trump. The billionaire real estate mogul's campaign has largely set aside the common refrains of social conservatives and the Republican Party of recent decades. Even the firestorm of late over his illegal-abortion-should-be-punished comments stemmed from being pressed while on the hot seat during a televised town hall, and weren't the result of his standard remarks on the stump.

Instead, Trump has concentrated on a populist-driven agenda, trying to convince those looking for work and wage solutions that he can bring jobs back from beyond U.S. borders and keep out immigrants, whom many in the working class believe are taking jobs from them.

But it's not as if the growing disconnect between a wide swath of potential Republican voters and the messaging of the Republican Party went unnoticed by the party itself. In a post-mortem report released after the 2012 election, GOP leaders called for the party to be "the champion of those who seek to climb the economic ladder of life."

"We have to blow the whistle at corporate malfeasance and attack corporate welfare," the report said. "We should speak out when a company liquidates itself and its executives receive bonuses but rank-and-file workers are left unemployed. We should speak out when CEOs receive tens of millions of dollars in retirement packages but middle-class workers have not had a meaningful raise in years."

Yet, combined with little economic progress for the working class and little leadership in Washington from Republicans on these issues, what's been a crucial Trump voting bloc remained angry and up for grabs. According to polling from the Pew Research Center, Trump supporters are more likely than backers of Sen. Ted Cruz or Gov. John Kasich to say that life for people like them in America is worse than it was 50 years ago. They're also far more likely to be angry at the federal government.

Skin-Color Suspicions

The U.S. is more diverse than ever, and only getting more so. Immigration has increased in recent decades, especially from Mexico , although the number of people trying to enter the U.S. illegally from there has decreased of late.

Many white working-class Americans have seen their own declining economic prospects as going hand-in-hand with this increasing diversity. In fact, according to the PRRI report, white working-class Americans were 20 points more likely than white college-educated Americans to think immigrants in the country illegally were taking Americans' jobs and causing economic problems.

Meanwhile, even as the 2012 Republican post-mortem called for a more inclusive attitude, racial tensions in the U.S. have erupted, notably in places like Ferguson, Missouri, and Baltimore following the police-involved deaths of unarmed African-Americans.

But plenty of white people in the U.S. weren't buying that there was a big problem, nor have they shared African-Americans' suspicion of police officers or law enforcement tactics. And back in 2009, 28 percent of white Americans thought President Barack Obama's policies aimed at improving the standard of living of blacks in the U.S. would go too far.

This perception likely contributed to an opinion among some whites that they are the ones being treated unfairly. And among the white working class, such opinions are especially rooted. In the PRRI survey, 60 percent said discrimination against whites had become as big a problem as discrimination against blacks and other minorities. Among Southern working-class whites, that number was a whopping 69 percent.

Trump, of course, hasn't exactly taken up the cause of multiculturalism or diversity. He's proposed banning Muslims from the country, called police officers "the most mistreated people" in America and stumbled when given the chance to immediately disavow support from a former leader of the Ku Klux Klan.